Along with hay fever and suddenly driving to work in daylight, one of the signs that spring has arrived for me is the arrival of flowering bluebells (Hyacinthoids
non-scripta). Every spring the dormant bulbs awaken in the depths of the soil and release shoots which rise up to the surface to form a carpet of thin
green leaves.
By April, the flowers emerge to give woodland understoreys the unmistakeable sea of blue, all across the country. The UK is home to almost half of the
global bluebell population and we are lucky in Surrey to have a number of sites which boast impressive annual displays. However, as an ecologist, my
interest in this species goes beyond just their aesthetic value.
Today bluebells are commonly used as an indicator species for identifying ancient woodland – areas which have been continuously wooded since at least 1600
AD – and which are therefore an important planning consideration as ‘irreplaceable habitat’. In fact, there is some evidence to suggest that bluebells
are even older still, as archaeological research has shown that bluebell roots were crushed and used as a glue for sticking feathers to arrows during
the Bronze Age. The almost mystical sight of a woodland of bluebells in full bloom has also inspired folklore over time, including the threat of impending
death if you are unlucky enough ever to hear a bluebell ring!
Considering our long cultural association with bluebells, you might not be surprised to discover that they are protected from being uprooted in the wild
by the Wildlife and Countryside Act 1981. This protection is vital as the bluebell is currently facing a number of threats. Cross-breeding with Spanish
bluebells (Hycinthoids hispanica), a non-native species which is paler and more upright than our native bluebell, continues to be a primary concern.
This common garden plant frequently escapes cultivation and can cross-breed with wild Hyacinthoids non-scripta to form hybrid bluebells (Hyacinthoids
x massartiana). As a result, our native populations are at risk of being diluted throughout the country.
Climate change poses another threat. The impacts are subtler but no less significant. Long-term studies looking at the first date of bluebells flowering
annually at Kew Gardens have found that, on average, the first flowering day has shifted to occur up to two weeks earlier over the past 30 years. This
may not sound like much, but such earlier emergence can lead to competition for light with other plant species also undergoing changing flowering schedules.
If trees in the woodland canopy come into leaf sooner as well, this can compound the issue by heavily shading the understorey at a time when bluebells
are trying to grow.
The future may seem bleak for our native bluebells, but awareness of the issues can lead to more effective management strategies to ensure the populations
return in force every year. Bluebells have been growing for hundreds of years and will hopefully continue to delight us for many more to come. I hope
you get a chance to walk through a bluebell wood in full bloom this spring, but don’t listen too closely for the sound of ringing bells…
